U.S. Pat. No. 3,801,875, entitled "Non-Metallic Load Center With Improved Bus Bar Construction", describes a molded plastic load center wherein the plastic case includes circuit breaker and branch strap mounting means integrally formed therein. The insulative properties of the plastic allows the circuit breakers to be compactly arranged without fear of electrical breakdown between the breakers or the terminal connections. The circuit breaker branch straps are mounted on the bottom surface of the plastic enclosure. Access to the terminal connections is made by unscrewing the cover from the case and lifting the cover away from upstanding tabs integrally formed within the case.
U.S. patent application Ser. No. 874,755, filed June 16, 1986, entitled "Molded Plastic Enclosure For Electric Service Apparatus", describes one such enclosure including an access door mounted on the cover for convenient access to the circuit breakers contained therein. A locking hasp is integrally formed on the door for padlocking the door against unauthorized access.
U.S. patent application Ser. No. 811,716, filed Dec. 20, 1985, entitled "Molded Plastic Enclosure For Disconnect Switches", wherein an access door is formed within the cover and hasp means are integrally formed within the cover for the arrangement of a padlock to prevent unauthorized access. The switches contained within the enclosure are of the type used with air conditioning disconnects. Both aforementioned Patent Applications are incorporated for reference purposes and should be reviewed for a good description of the relationship between the molded plastic door, cover and case used for housing both circuit breakers and electric switches.
Although non-metallic load centers have found limited application over the past few years, wide market acceptance has not, as yet, been realized mainly due to the lower cost of comparable metallic load centers. The purpose of the instant invention is to described a molded plastic enclosure for circuit breakers wherein the three plastic enclosure components are formed on automated equipment and wherein the metallic components are inserted by means of a completely automated process. It has since been determined that the savings realized by complete automation results in a molded plastic circuit breaker enclosure that is less expensive than comparable metallic circuit breaker enclosures.